... expressed doubts about this. Among them was De Beer (1924) , who claimed that the pituitary anlage arises before the appearance of the stomodeum in Amphibia. More recently, Takor and Pearse (1975) proposed a new hypothesis for the chick embryo, that the adenohypophyseal anlage is derived from...

..., paving the way for understanding the inductive action of the organizer. 25 07 1990 © 1990 by Company of Biologists 1990 induction regulation neural system amphibia The purpose of this article is to review some recent progress made on different research fronts...

...L. Dennis Smith 21 09 1989 © 1989 by Company of Biologists 1989 oocyte maturation induction transmembrane signaling regulation cell cycle MPF amphibia The induction of oocyte maturation is known to involve an initial action of agonists at the oocyte surface...

...). In all forms studied, the first pair of somitomeres abut the prosencephalon, but caudal to that, for each tandem pair of somitomeres in the amniote and teleost, there is but one somitomere in the amphibia. The mesodermal segments of the shark embryo are arranged like those of the amphibia. Copyright ©...

... is discussed. Copyright © 1988 by Company of Biologists 1998 segments development vertebrate Amphibia mesoderm Pattern formation is essentially a matter of integrating the genetically determined activities of individual cells. This view implies that there exists, at the tissue level, some...

..., it was present on the mitotic chromosomes. Its association with mitotic as well as lampbrush chromosomes connects it with the DNP fibre proteins. 07 08 1987 © 1987 by Company of Biologists 1987 oocyte nuclear proteins lampbrush chromosomes monoclonal antibodies amphibia Pleurodeles waltl...

... induction. If, as suggested for some cases studied in amphibia ( Kaneda, 1981 ; Kurihara & Sasaki, 1981 ; Kaneda & Suzuki, 1983 ), the propagation of an induced state is accompanied by alteration in the cell types specified, such a process could be part of the mechanism for establishing...

... it. Xenopus Amphibia mesoderm induction cell movement gastrulation mesoderm-inducing factors developmental clocks. Inductive interactions play a major role in the diversification of cell types during vertebrate development (reviewed by Smith, 1987 a ). The first such interaction in amphibian...

... is not described by Straznicky & Hiscock and our histogenetic studies between 2 and 12 months after metamorphosis show no such asymmetry. retina optic tectum histogenesis amphibia ocular migration Xenopus laevis autoradiography The amphibian retinotectal projection was established...

... formation and middle- to late-bud blastemas were found at the end of 11 or 14 days treatments with retinol palmitate. 23 09 1985 Copyright © 1986 by Company of Biologists 1986 retinoids regeneration amphibia Pleurodeles waltl Triturus vulgaris Vitamin A and its analogues...

... projection. Within the limits imposed by neuroanatomical assessment of the projection, it was found to display at least general retinotopic order. amphibia visual deprivation Xenopus laevis retinotectal projection neural activity Copyright © 1986 by Company of Biologists 1986 09...

... timing mechanisms nucleocytoplasmic ratio DNA replication cytoplasmic clock amphibia maturation promoting factor (MPF) Time is an indispensable element in any interpretation of embryological development. It is obvious that a better understanding of the temporal control of development...

... interactions for mesoderm and endoderm formation are discussed. Copyright © 1985 by Company of Biologists 1985 inductive interaction competence determination amphibia Before describing the individual inductive interactions occurring successively in the developing amphibian egg and embryo...

... antibodies amphibia Copyright © 1985 by Company of Biologists 1985 ...

.... ( 1979 ). Somitogenesis in amphibia. II. Origins in early embryogenesis of two factors involved in somite specification . J. Embryol. exp. Morph . 53 , 245 – 256 . García-Bellido , A. , Lawrence , P. A. , & Morata , G. ( 1979 ). Compartments in animal development . Sci...

... for the chick factor. Copyright © 1985 by Company of Biologists 1985 specification induction neural induction mesoderm induction Concanavalin A amphibia tunicamycin cyclic AMP Calcium ionophore A 23187 By the well-known implantation experiment of Spemann & Hilde Mangold...

... for failure to transfer dye also fail to transfer small ions. Copyright © 1985 by Company of Biologists 1985 gap junctions electrophysiological coupling Lucifer Yellow Texas Red gap junction protein – antibody to mesoderm induction neural induction amphibia Cells of the early...

... by Selman & Perry (1970) have shown that this junction is formed by a close approach and the subsequent contact of the ridges of opposing blastomeres. But the three-dimensional features of this process are still uncertain. Cleavage amphibia SEM cell surface newt Cynopus (Triturus...